KR20010101579A - Vehicle liftgate power operating system - Google Patents

Abstract

A power drive system for opening and closing the vehicle lift gate has a pair of drive units supported on the vehicle roof and is connected to the lift gate to open and close the lift gate. Each drive unit includes a bracket that is fastened to the vehicle body to support various parts including the reversible electric motor, gear unit and track. The electric motor drives the segment sectors inside the track via the reduction gear unit. The segmental sector includes an arcuate link that slides into an arcuate track portion of the track and a plurality of short sector links that are stored in the storage track portion when the liftgate is closed. Since the arcuate link is stretched and retracted by the segmented rack, the arcuate link has an outer end pivotally connected to the liftgate to open and close the liftgate.

Description

Vehicle Liftgate Power Driving System {VEHICLE LIFTGATE POWER OPERATING SYSTEM}

Utility vehicles and vans with lift gates that are hinged at the top in the horizontal axis as a whole are used by many people today. Some of these lift gates are large and heavy. Its size and weight make it difficult for some liftgates to open and close. Some liftgates are also far off the ground when they are fully open. The height from the ground can make it very difficult for some people to close the lift gate. For these and other reasons many people want to have a power drive system that opens and closes the lift gate.

Many other liftgate owners have recently tried. Some of the liftgate owners have a single cable that opens and closes the liftgate in connection with an equilibrium system such as a gas cylinder. Liftgates with a single cable opening and closing means are generally trunk lids which are light and have a relatively small range of motion.

The output of the gas cylinder changes with temperature. This complicates power liftgate systems that rely on gas cylinders to open the liftgate. The gas cylinder or gas cylinders must be strong enough to open the lift gate even on the coldest days (-40 ° C.). This results in a substantially increased closing resistance on the hottest days (80 ° C.) of the gas cylinder. Therefore a very large electric motor must be used to close the lift gate.

Liftgates with two or more gas cylinders are common for equilibrium systems. These gas cylinders are generally positioned on an axis substantially parallel to the liftgate, causing the gas cylinders to be hidden when the liftgate is closed. In this closed position the moment arm of the gas cylinder is very small. In such systems the liftgates will have to move by about one third of their full operating range before applying sufficient force to open the liftgate without additionally applying an independent lifting force. There are even some systems that bias the lift gate to the closed position when the gas cylinder passes through the center and the lift gate is closed. In this self-closing system, the liftgate may need to open more than one-third before the gas cylinder opens the liftgate further.

The force required to stop the liftgate at a given position along the path of movement from the closed position to the fully open position is substantially varied in some liftgate open systems. The power lift gate closing device must apply the combined force sufficient to stop the lift gate at any given position along the path of movement, the force to overcome friction, and the force to accelerate the lift gate during lift gate closing. If the total force exerted by the liftgate closing device varies substantially from one position between full opening and closing to another position between full opening and closing, the control system detects the disturbance and lifts the vehicle or lift gate. It will be difficult to stop the lift gate without damaging the blocking object.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power drive system for a vehicle lift gate rotatably attached to a vehicle compartment for pivotal movement about a general horizontal axis, and more particularly to a fully open position of the lift gate in a closed position. And a power drive system that moves from the open position to the fully closed position.

Preferred embodiments of the present invention are shown in the following figures.

1 is a perspective view of the rear of a vehicle equipped with the liftgate power drive system of the present invention showing that the liftgate is in an open position.

FIG. 2 is an enlarged perspective view of the right hand drive unit of the power drive system of FIG. 1 showing the drive unit when the lift gate is closed; FIG.

3 is an enlarged side view of the right drive unit shown in FIG. 2 with portions removed to illustrate internal details.

4 is an enlarged side view of the right drive unit shown in FIG. 2 with portions removed to show internal details when the lift gate is in the open position.

5 is a view in the direction of the arrow actually cut along the line 5-5 of FIG.

It is an object of the present invention to provide an improved vehicle liftgate power drive system.

A feature of the present invention is that the vehicle liftgate power drive system can move the liftgate from the open position to the fully closed position as well as from the closed position to the fully open position.

Another feature of the present invention is that the liftgate power drive system allows the liftgate to be moved manually when sufficient gear train is selected.

Another feature of the present invention is that the power drive system can be stopped at any position to place the lift gate at any intermediate position without the need for brakes, detents, or the like.

Another feature of the invention is that the drive unit of the liftgate power drive system may be shaped to embrace an internal roof structure and consequently guided by a track that maximizes the loading height unobstructed by the liftgate passageway and is connected to the liftgate. Has a movable link attached.

Another feature of the invention is that the liftgate power drive system can be stored close to the interior roof of the vehicle and thus by segmental segments that can minimize the intrusion of unloaded loading height into the cargo area of the vehicle and the liftgate passageway. It is activated and has a movable link attached to the lift gate.

Another feature of the invention is that the liftgate power drive system has a movable link attached to the liftgate so that it is formed and guided to move concentrically with respect to the pivot axis of the liftgate so that the movable link can be easily sealed. To ensure that This also allows the outlet for the movable link to be located outside of the seal around the liftgate.

Another feature of the invention is that the power drive system can be used in connection with a balance system for a manual drive system with any modified balance system.

The above and other objects, features, and advantages of the present invention will become more apparent from the following description of the preferred embodiment in conjunction with the drawings.

Vehicle 10 has a lift gate 12 attached to the end of the vehicle roof by two hinge assemblies. A typical right hinge assembly 14 is shown in FIGS. 2, 3 and 4.

The hinge assembly 14 has a hinge portion 16 fastened to the roof groove of the vehicle 10 and a hinge portion 18 fastened to the upper groove of the lift gate 12. Hinge portion 18 is attached to hinge portion 16 by pivot pin 20 such that liftgate 12 is shown in FIGS. 1 and 4 in the closed position shown in FIGS. 2 and 3 with respect to pivot axis 21 shown in FIGS. 2, 3 and 4. Turn to the raised open position. Pivot axis 21 is generally substantially parallel and liftgate 12 is generally allowed to pivot about 90 ° with respect to pivot axis 21. However, the range of movement can vary substantially from any vehicle 10 to another vehicle.

The lift gate 12 is opened and closed by a power drive system comprising two identical drive units 22 mounted at the end of the vehicle roof. The drive units 22 are arranged near each vertical body column at the end of the vehicle 10 which is arranged laterally from one another and defines a rear passage closed by the lift gate 12. A typical drive unit 22 is shown with the inner decorative cover 23 removed to show the details of the drive unit in FIGS. 2, 3 and 4.

Each drive unit 22 is a vehicle in a fixed position to support a number of parts including a reversible electric motor 26, a reduction gear unit 28, and a two-piece track orbit 30 having a track support 31 and a track cover 32. And a bracket 24 fastened to the body. The electric motor 26 has a worm gear output 27 that drives the pinion gear 28a of the reduction gear unit 28. Pinion gear 28a drives output gear 28b through a splined stub shaft 28c to provide speed reduction and torque increase.

The two-piece track 30 includes a rear track portion 30a and a continuous front track portion 30b that are fastened to the vehicle body in a fixed position. Hanger 37 attaches the end of track 30 while bracket 24 attaches the inner end of rear track portion 30a through the housing of gear unit 28.

The rear track portion 30a is preferably shaped to embrace the end of the vehicle roof, in particular a box beam carrying the hinge portion 16 as well shown in FIGS. 2 and 3 in order to maximize unobstructed loading height in the liftgate passageway. It is. The track portion 30a is also preferably arcuately shaped with a radius of curvature about the hinge axis 21 of the liftgate 12. The front track portion 30b is preferably located above the arcuate rear track portion 30a and directed in the opposite direction to create a wave like the appearance of the track 30 closely following the inner contour of the vehicle roof. This wave-like contour and closing distance reduces the need for space and in particular reduces interference with the luggage compartment in the vertical direction.

Segment sector 36 is arranged on track 30. Segmented sector 36 includes a plurality of elongated links 36a and short links 36b that are connected in end-to-end fashion in a chain-like fashion to pivot. The link 36 is also preferably arcuately curved to correspond to the track portion 30a so that the link 36 is centered on the axis 21 between the retracted position shown in FIGS. 2 and 3 and the extended position shown in FIGS. 1 and 4. And to slide back and forth within the track portion 30a which is pivoting. This concentric movement path reduces the turning movement of the link 36a with respect to the lift gate 12 and consequently the link 36a can be easily sealed at the outlet of the vehicle body, and the body outlet for the link 36 is even sealed around the lift gate. It may be located on the outer vertical body pillar (not shown).

Sector link 36b is stored in front track portion 36b when liftgate 12 is closed as shown in FIG. 3 and then moves to rear arcuate portion 30a when liftgate 12 is opened as shown in FIG. . As a result, sector link 36b is preferably made of short, curved links to facilitate movement within track 30, such as a wave.

The inner end of link 36a preferably comprises an integral sector link 36c connected to pivot to the outer end of the first short sector link 36b. The outer end of the arched link 36a is connected to pivot to the lift gate 12. The integrated rack link 36c provides better control of the start and stop movement of the arched link 36a. The inner end of the arcuate link 36 carries a roller 38 in the pivotal connection with the first short sector link 36b to facilitate slipping in the track 30. The inner ends of the remaining sector links 36b also carry rollers 38 in their respective pivotal connections to facilitate sliding in track 30.

The power drive system additionally includes suitable motor control to power and shut off conventional power sources such as vehicle batteries (not shown) and reversible electric motors 26. Motor control is well known to those skilled in the art and therefore detailed description is omitted.

The power drive system works as follows. Assuming lift gate 12 is closed as shown in FIGS. 2 and 3, electric motor 26 is powered to open lift gate 12. When power is transmitted, electric motor 26 rotates pinion gear 28a counterclockwise. The pinion gear 28a rotates the output gear 28b counterclockwise in turn until the arcuate link 36a moves from the retracted position shown in FIGS. 2 and 3 to the extended position shown in FIGS. Drive 36c and then drive sector link 36b in turn. This operation raises the lift gate 12 from the closed position located in FIGS. 2 and 3 to the open position shown in FIGS. 1 and 4. When the lift gate 12 is fully open, a limit switch or the like is activated to shut off the electric motor 26. The lift gate 12 is closed by reversing the electric motor 26 and the gear unit 28 drives the segment sector 36 to return to the retracted region shown in FIGS. 2 and 3.

In a suitable motor control circuit, the electric motor 26 can remove power at any moment, so that the lift gate 12 can stop at any intermediate position and maintain its intermediate position due to the friction of the gear train 28 without the help of brakes or detents. Can be. The liftgate 12 can then be moved by the powered electric motor 26 or the liftgate 12 can be moved manually because the gear train 28 can be designed to have sufficient efficiency to allow reverse drive to the electric motor 26.

The power drive system can be designed to drive independently or in conjunction with a gas cylinder 40 well known in the art, which is preferentially adapted to the size of the electric motor 26.

The power drive system preferably comprises two identical drive units 22 for reducing balanced operating and maintenance costs. However, the drive units need not be identical and in some cases a single drive unit may be suitable.

It is also possible to use two drive units with a single reversible electric motor that drives both gear trains 28. In this arrangement, the shaft of the electric motor is parallel to the axes of many gears in gear train 28, which makes it possible to eliminate the need for cross-axis gear arrangements and possible needs of clutches, thus reversing the electric motor and thus lifting the liftgate manually. It can work. The same applies to a power drive system in which the axes of the individual electric motors have two identical drive units parallel to the axes of each drive train.

Obviously, many modifications and variations will be possible in accordance with the present invention. Therefore, implementations other than those described in detail within the scope of the present technology may be possible.

The present invention relates to a power drive system for a vehicle lift gate rotatably attached to a vehicle compartment for rotational axis movement, which is a generally horizontal axis, wherein the lift gate is in a fully open position in a closed position and a fully closed position in an open position. To provide a motorized driving system.

Claims (12)

At least one drive unit comprising a reversible electric motor, a segment sector driven by the electric motor, a track and a link slipped therein, one end attached to the lift gate and the other end attached to the segment sector; , A power drive system that opens and closes a vehicle lift gate, generally attached to pivot at the end of the vehicle roof for pivotal movement between the open and closed positions about a horizontal axis. 2. The drive unit according to claim 1, wherein the drive unit includes a gear train between the electric motor and the segment sector, the gear train having sufficient friction to stop the vehicle lift gate in an intermediate position without the help of a brake or the like. Motorized driving system. 3. The power drive system of claim 2, wherein the gear train has an efficiency that enables manual movement of the vehicle lift gate from an intermediate position. 2. The vehicle lift gate of claim 1 wherein the vehicle lift gate exposes a lift gate passageway in an open position, and wherein the track extends the end of the vehicle roof to increase unobstructed loading in the passageway of the lift gate when the lift gate is in the open position. A power drive system, characterized in that it is formed to hug. The track of claim 1, wherein the track has an arcuate rear portion with a radius of curvature about a hinge axis, and the link is also arcuately shaped to correspond to the curvature of the track such that the link pivots about a hinge axis. A power drive system that slides back and forth within the track. 6. The power drive system according to claim 5, wherein the track is wavy and has a front portion for storing at least a portion of the segment track when the liftgate is in the closed position. 7. The method of claim 6, wherein the segment sector has a plurality of sector links, the arcuate segment has an integral sector link at the inner end, and the sector links are pivotally connected at the end and the end in a chain-like form. Power drive system, characterized in that. Vehicle frames and passage entrances; A lift gate pivotally attached to the vehicle frame adjacent the upper portion of the passageway entrance for pivotal movement about a common horizontal pivot axis; Includes a reversible electric motor, gear unit, track, The track includes a rear arcuate portion and a front storage track portion secured to the vehicle body, A drive unit supported by the frame and connected to the lift gate to open and close the lift gate; Segmented sectors arranged in the track including an arcuate link and a plurality of short sector links sliding within the arcuate track portion; And An electric motor having a gear output for driving said segment sector through a gear unit, And the arcuate link opens and closes the lift gate of the vehicle having an inner end pivotally connected to an end of one of the short sector links of the segment sector and an outer end coupled to the lift gate. 9. The vehicle lift gate of claim 8 wherein the vehicle lift gate exposes the lift gate inlet in an open position and the track is wavy and formed to embrace the end of the vehicle roof so that it is not obstructed at the lift gate inlet when the lift gate is in the open position. Power drive system characterized in that to increase the unloading. 10. The method of claim 9, wherein the track has an arcuate rear portion with a radius of curvature about a hinge axis, and the link is also arcuately shaped to have a curvature corresponding to the curvature of the track, such that the link is hinged. And to slide back and forth within the track orbiting about an axis. 11. The power drive system of claim 10, wherein the track has a front portion to store at least a portion of the segment track when the lift gate is in the closed position. 12. The method of claim 11, wherein the segment sector has a plurality of sector links, the arcuate segment has an integral sector link at the inner end, and the sector links are pivotally connected at the end and end in a chain-like fashion. Power drive system, characterized in that.